1. Field of the Invention
The present invention relates to an exposure compensation device for an auto exposure camera, and in particular, relates to an exposure compensation device which automatically sets the lens aperture and the shutter speed to appropriate values through photometry.
2. Description of the Related Art
The selection of a proper aperture value is important for obtaining satisfactory pictures with an optical camera. Automatic exposure control devices are known for use in optical cameras. In general, known automatic exposure control devices select an appropriate aperture value and a shutter speed using calculations based on a film speed and photometry results.
However, to take pictures at under-exposure or over-exposure conditions, producing a desired result requires a certain degree of freedom. Thus, it is necessary to perform an exposure compensation operation. There are various proposals for methods of setting an exposure compensation amount with respect to an appropriate exposure value, as computed by the camera, using a separate independent exposure compensation device. In general, the known methods are directed toward two specific cases. In the first case, a fixed exposure compensation amount is needed for all pictures taken on a specified film, in the second case, various changes are needed in the calculated exposure compensation amount, such as when calculating the appropriate exposure value is a problem in normal automatic exposure, regardless of the film being used.
Conventional methods of setting an exposure compensation amount allow an exposure compensation amount to be selected by operating an independently attached operation button or rotating a dial on which exposure compensation amounts are identified. In these known methods, not only are special operation buttons necessary, but the operations are complicated and time consuming, which increases the likelihood of missing photo opportunities.
Moreover, there are problems associated with compensating the exposure by a fixed amount for an entire roll of film. For example, even if a picture is taken in which the exposure compensation amount is changed for a single roll, there is a danger that the photographer may forget to cancel the exposure compensation setting for the next roll. In conventional cameras, a display of the exposure compensation amount is only performed as an exposure compensation button is being pushed. Further, known exposure compensation devices typically only display a cryptic mark indicating an exposure compensation operation.
Another problem in setting the exposure compensation amount is that the automatic exposure mode of the camera, for example, a program mode, a shutter priority mode and an aperture priority mode, changes the exposure compensation operating procedure of the camera. That is, it is necessary to consider the exposure compensation operating procedure in the respective automatic exposure modes when setting the exposure compensation amount.